Question 1

A confidence interval constructed around a point prediction from a regression model is called a prediction interval,because the actual point being estimated is not a population parameter.

Accepted Answer

A) True 
 B)False  True

Question 2

In order to test the significance of a multiple regression model involving 4 explanatory variables and 40 observations,the numerator and denominator degrees of freedom for the critical value of F are 4 and 35,respectively.

Accepted Answer

A) True 
 B)False  True

Question 3

Heteroscedasticity means that the variability of Y values is larger for some X values than for others.

Accepted Answer

A) True 
 B)False  True

Question 4

Which of the following would be considered a definition of an outlier?

Accepted Answer

A)  An extreme value for one or more variables
B)  A value whose residual is abnormally large in magnitude
C)  Values for individual explanatory variables that fall outside the general pattern of the other observations
D)  All of these choices

Question 5

In multiple regression with k explanatory variables,the t-tests of the individual coefficients allows us to determine whether  (for i = 1,2,….,k),which tells us whether a linear relationship exists between  and Y.

Accepted Answer

A) True 
 B)False

Question 6

When determining whether to include or exclude a variable in regression analysis,if the p-value associated with the variable's t-value is above some accepted significance value,such as 0.05,then the variable

Accepted Answer

A)  is a candidate for inclusion.
B)  is a candidate for exclusion.
C)  is redundant.
D)  does not fit the guidelines of parsimony.

Question 7

In regression analysis,the total variation in the dependent variable Y,measured by  and referred to as SST,can be decomposed into two parts: the explained variation,measured by SSR,and the unexplained variation,measured by SSE.

Accepted Answer

A) True 
 B)False

Question 8

Which definition best describes parsimony?

Accepted Answer

A)  Explaining the most with the least
B)  Explaining the least with the most
C)  Being able to explain all of the change in the response variable
D)  Being able to predict the value of the response variable far into the future

Question 9

Multicollinearity is a situation in which two or more of the explanatory variables are highly correlated with each other.

Accepted Answer

A) True 
 B)False

Question 10

In regression analysis,homoscedasticity refers to constant error variance.

Accepted Answer

A) True 
 B)False

Question 11

Which of the following is the relevant sampling distribution for regression coefficients?

Accepted Answer

A)  Normal distribution
B)  t-distribution with n-1 degrees of freedom
C)  t-distribution with n-1-k degrees of freedom
D)  F-distribution with n-1-k degrees of freedom

Question 12

Suppose you forecast the values of all of the independent variables and insert them into a multiple regression equation and obtain a point prediction for the dependent variable.You could then use the standard error of the estimate to obtain an approximate

Accepted Answer

A)  confidence interval.
B)  prediction interval.
C)  hypothesis test.
D)  independence test.

Question 13

In simple linear regression the test statistic for testing  is t-distributed with n - 2 degrees of freedom.

Accepted Answer

A) True 
 B)False

Question 14

A scatterplot that exhibits a "fan" shape (the variation of Y increases as X increases)is an example of

Accepted Answer

A)  homoscedasticity.
B)  heteroscedasticity.
C)  autocorrelation.
D)  multicollinearity.

Question 15

In a simple linear regression model,testing whether the slope  of the population regression line could be zero is the same as testing whether or not the linear relationship between the response variable Y and the explanatory variable X is significant.

Accepted Answer

A) True 
 B)False

Question 16

Determining which variables to include in regression analysis by estimating a series of regression equations by successively adding or deleting variables according to prescribed rules is referred to as _____ regression.

Accepted Answer

A)  elimination
B)  forward
C)  backward
D)  stepwise

Question 17

Forward regression

Accepted Answer

A)  begins with all potential explanatory variables in the equation and deletes them one at a time until further deletion would do more harm than good.
B)  adds and deletes variables until an optimal equation is achieved.
C)  begins with no explanatory variables in the equation and successively adds one at a time until no remaining variables make a significant contribution.
D)  randomly selects the optimal number of explanatory variables to be used.

Question 18

A multiple regression model involves 40 observations and 4 explanatory variables produces SST = 1000 and SSR = 804.The value of MSE is 5.6.

Accepted Answer

A) True 
 B)False

Question 19

In testing the overall fit of a multiple regression model in which there are three explanatory variables,the null hypothesis is  .

Accepted Answer

A) True 
 B)False

Question 20

The objective typically used in the tree types of equation-building procedures is to find the equation with

Accepted Answer

A)  a small se.
B)  a large R2.
C)  a small se and a large R2.
D)  the smallest F-ratio.

Exam 11: Regression Analysis: Statistical Inference

A confidence interval constructed around a point prediction from a regression model is called a prediction interval,because the actual point being estimated is not a population parameter.

In order to test the significance of a multiple regression model involving 4 explanatory variables and 40 observations,the numerator and denominator degrees of freedom for the critical value of F are 4 and 35,respectively.

Heteroscedasticity means that the variability of Y values is larger for some X values than for others.

Which of the following would be considered a definition of an outlier?

In multiple regression with k explanatory variables,the t-tests of the individual coefficients allows us to determine whether (for i = 1,2,….,k),which tells us whether a linear relationship exists between and Y.

When determining whether to include or exclude a variable in regression analysis,if the p-value associated with the variable's t-value is above some accepted significance value,such as 0.05,then the variable

In regression analysis,the total variation in the dependent variable Y,measured by and referred to as SST,can be decomposed into two parts: the explained variation,measured by SSR,and the unexplained variation,measured by SSE.

Which definition best describes parsimony?

Multicollinearity is a situation in which two or more of the explanatory variables are highly correlated with each other.

In regression analysis,homoscedasticity refers to constant error variance.

Which of the following is the relevant sampling distribution for regression coefficients?

Suppose you forecast the values of all of the independent variables and insert them into a multiple regression equation and obtain a point prediction for the dependent variable.You could then use the standard error of the estimate to obtain an approximate

In simple linear regression the test statistic for testing is t-distributed with n - 2 degrees of freedom.

A scatterplot that exhibits a "fan" shape (the variation of Y increases as X increases) is an example of

In a simple linear regression model,testing whether the slope of the population regression line could be zero is the same as testing whether or not the linear relationship between the response variable Y and the explanatory variable X is significant.

Determining which variables to include in regression analysis by estimating a series of regression equations by successively adding or deleting variables according to prescribed rules is referred to as _____ regression.

Forward regression

A multiple regression model involves 40 observations and 4 explanatory variables produces SST = 1000 and SSR = 804.The value of MSE is 5.6.

In testing the overall fit of a multiple regression model in which there are three explanatory variables,the null hypothesis is .

The objective typically used in the tree types of equation-building procedures is to find the equation with